Treatement of fatty compositions and product



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TREATMEN or FA'rrycomosrrIoNsYjf jf V GeorgeJD. Martin, Nitro, W. Va.,assignor to H a Monsanto Chemical Company, St. Louis, Mo., a

corporation of Delaware .Serial No. 242.291

I Nol)r-awing. ApplicationNovember 251938;

e invention relates to the-stabilizatiomof compoaitionscontaining afatty component and f particularly to the prevention-oitheir decompmsiticnorrancidiiication. 1 a

'5 at i well known that oxidizable mam "such assoap, and especiallywhitesoap, tend to '7 1 deteriorate upon aging as evidenced bydevelopment cfcolor and rancid'odon, These-obnoxio'uscharacteristicsareparticularly noticeable inthe J case of soaps madefrom, oils which themselves quickly become rancid, as i'orexample, oliveoil, cottonseed oil; palmoil, palm kernel oil, peanut 2 oil andthe like.Rancidityand color formation are known to be acceleratedgby variousagents such as heat,jsunlight, ultraviolet light and certain metals suchas copper. --It .is obviously de' sirable to counteract these'accelerating agents andithe' natural tendency'oi oxidizable i'attymate'rlals to deterlorate'with age;

9 -Among the objects otthe present invention is the inhibiting orretarding the. deterioration of o'xidizable fatty materials, as for.examplamvege. table oils and soaps. y Y

- v I v Anotherobj 't of the invention I 28 I tion of anew andimprovedvegetable oil or soap.

7 Ithas-been. discovered in .acccrdance with the present inventicnthatthiourethanes are eflective stabilizers of oxidizable iatty zmaterials.The

thiourethanes comprise the estersoithiocarbamic so acid'sand areconvehientlydesigtiated by the 1 01- I whereinR and Rrrepresent'hydrogen, -my1.

ary1, aralkyl and alicyclic groups and R's-reprev1 sent: an esterformingf-radical asdor example i alkyl, aryl; aralkyl and alicyclicgroups.

. 40o Typicalexamples othe prei'erred class'oi stabilizers oioxidizablefiattymaterials are N-phenyl ,thioin'ethane' 1 v I 1'y-ommpmgiamalgam I benzylthioureths e ,2 I

I I, 0 I -cyclchcxyl'thiourethanc (Cl. 23-256) s N-phenylbcta (dibetahydrory'ethyl) 1 1 amino ethylthiourethsne ll-pbiphenylthiourethsnc Imammal, hydrory ethylthiourethsne I; 15

' N-butylthlourethane 'j cimfiN- -o-oeclm I Nsmy moimtm analogues andequivalents thereof} ,5 :2 One methbd for. the preparation oi; thiourePhenylthiourethsns thanesis by theactionoiammonia oranamine ona xanthic'ester althoughsother-methodshave' 1 been described inthechemicalliterature andmay:

be employed when desired. For example; s nusy tard oil'such as phenylmustard. on maybe rel-J; 5:; I, acted withan alcoholor a phenoliin thepresenee 1 oicaustic soda to produce a thiourethanez The I g Irthiourethanesiinjgeneral are' a'wellclass; I 1

oi 'coinpoundsand the present inventicn is'in no-" 40 v wise limitedtotheirvpreparaticnu i p The iollowing-are typical methods e'mployed'inI testing the preierred matezialsiandare specific embodiments oi theinvention showingthe'usetul 15 and valuable properties oi 'the"preferred I classof I j J compounds and are intended to illustratejtheini-t .ventlon but in nowise tolimit the same. I

I A substantially neutral-soap, was prepared 1W) saponiiying a mixtureof. substantially 3 parts by weight oinan edible tallow andsubstantially. 1'

part by weight oi cocoanut oil I f droxide; substantially 021%based onthe weight; oi the vsoap of one ofthe preferred stabilizers wasincorporated therein'by a suitable meansr iflve grams of the treatedsoapwereplaced i1 250 c. c. "iodine' flaskand alpiec'e oir fllteripaper,saturated with water was tom to sinallssp e'ces and placed in theiiask.The flask was thewtightly stoppered and placed in anfoven maintainedjataconstant temperature of C. At the endoi'ijd each day the color of thesoap under test was noted, also the stopper was removed, and any odorindicative of rancidity noted. Similar tests were carried out with thesame soap to which no stabilizer was added and the periods of stabilitycompared. The period during which the soap containing typical examplesof the preferred class of materials did not develop rancidity orsubstantially discolor is given in the following table.

Table I The period of stability for the identical soap containing noadded stabilizer thereof was found on testing in the above describedmanner to be approximately four days.

From the data hereinbefore set-forth it is readily shown that thepreferred class of compounds constitute an important class of soapstabilizers.

As further specific embodiments of the present invention a convenientquantity, for example 0.01% to 1.0% by weight of any of the abovepreferred class of stabilizing agents may be incorporated in fatty acidcompounds generally, including oils, such as animal or fish oils or avegetable oil, for example olive oil. As a means of testing thestabilizing action thereof, the treated oil is heated in an open flaskfor several days in an oven maintained at 50 C. After various intervalsof time samples of the aged oils are tested in a manner analogous tothat described by D. H. Wheeler, Oil and Soap, vol. 9, page 93, 1932.Thus five grams of olive oil are dissolved in 50 c. c. of solventmixture 7 (60 percent of glacial acetic acid, 40 percent of chloroform)and 1 c. c. of saturated potassium iodide solution added. After exactlyone minute from the time of the addition of the potassium iodide, 100 c.c. of water are'added and the liberated iodine titrated with 0.01 Nsodium thiosulfate, employing starch as indicator. The titration incubic centimeters is a measure of the peroxide formation andconsequently a measure of the stability of the oil, a low figureindicating little peroxide formation or in other words good stability.The titration figures obtained on heating the olive oil for differentperiods of time at 50 C. in the absence of and in the presence of 0.1%by weight of the new class of stabilizing agents is given in Table II.

Table II From the data set forth in Table II it is shown that thepreferred'class of compounds exhibit exceptional stabilizing propertieswhen incorporated in oxidizable fatty materials, for example vegetableoils.

As further specific embodiments of the invention showing the stabilizingproperties of the preferred class of compounds in vegetable oils and inother oxidizable fatty materials, a typi-- cal member of the preferredclass of materials. for example N-phenyl thiourethane, was tested inoleic acid and in cottonseed oil in the manner described above and foundto exhibit desirable stabilizing properties.

The amount of the selected one or mixture of the preferred substanceswhich may be added to the ordinary soap, or soap stock, or ingredientsused in the manufacture thereof, for effeoting the desired result, maybe varied, but in general it will be found that good results may beobtained by adding, upon a weight basis, from 0.01% to 1.0% of thestabilizing agent to the soap or soap stock.

In operating the present invention, the stabilizing agent may beintroduced at any stage of the process of soap manufacture. Furthermore,where convenient or desirable the preferred class of stabilizers may beincorporated in the form of an aqueous caustic solution. For example,after the fatty acid has been obtained in the usual manner and has beensaponifled to produce a soap stock, the products comprising thepreferred stabilizers may be incorporated therein. The soap product maythen be dried in the usual manner and may be marketed in cakes, flakes,or any other form as may be desired. Further, if desirable, thestabilizing agent may be incorporated into the dry soap in the wellknown crutching process. Moreover, the stabilizing agent mayconveniently beadded to the oils, fats or fatty acids beforesaponiflcation. Again the compounds of the present invention may beemployed in conjunction with oxidizable fatty materials including soapsand fatty oils broadly as stabilizers thereof.

Other methods of testing the stability of fatty acid compounds thanthose specifically disclosed may be employed, as is well known to thoseskilled in the art to which the present invention pertains.

The present invention is limited solely by the following claims attachedhereto as part of the specification.

What is claimed is:

1. An oxidizable fatty material stabilized against the development ofcolor and rancidity by having incorporated therein a small amount of acompound possessing the structure it B: 8

wherein R1 and R2 are selected from a group consisting of hydrogen,alkyl, aryl, aralkyl and allcyclic groups and R3 represents an esterforming group. 7 v

2. An oxidizable fatty material stabilized against the development ofcolor and rancidity by having incorporated therein a small amount of anN-aryl thiourethane.

3. An oxidizable fatty material stabilized against the development ofcolor and rancidity by having incorporated therein a small amount of anN-alicyclic thiourethane.

4. An oxidizable fatty material stabilized by having incorporatedthereina small amount J of an N-cyclohe'xyl thiourethane.

6. An. oxidizable fatty material .stabilized I I against the developmentof color-andrancidity' .by having incorporated therein a small amount,ot a thiourethane wherein the ester forming :radicalis an alkyl groupcontainingfl more' than twocarbon atoms.

7. An oxidizable 'fatty material stabilized against the development ofcolor and rancidity by having incorporatedth erein a small amount of anN-phenylj alkyl thiourethane wherein the said alkyl group contains morethan two carbon atoms. a

compound possessing the wherein R1 and R: are selected from a group[consisting 01' hydrogen, alkyl, aryl; aralkyl and .alicyclic groups andIt: represents an ester forming group. a

9. A soap stabilized against the development of I color and rancidity byhaving incorporated therein a small amount of an N-aryl ,thiourethane.

10. A soap'stabilized against the development a. A soap stabilizedagainstthe development or color and rancidity by-having incorporatedthere- 1 in a small amount of a structure thane.

11. A soap stabilized against thefdevelopinent"? 0! color and rancidityby having incorporated therein a smallamount of anN-phenyl thiour e-'thane.

of color andrrancidity by having in f a m vcuc mauve-1 12. A so pstabilized against the developmem "of color and rancidity. by havingincorporated therein a small amount of an N-cyclohexyl thlo urethane. a1

against the development 13. A soap stabilized I of color and ranciditybyh'aving incorporated therein a smallamount of a thlourethane wherein theester forming radical is an alkyl group containing more than two carbonatoms.

14. A soap stabilized 'against the development of color and rancidity byhaving incorporated '1 therein a small amountot an N-phenyl ,allgvlthiourethane whereinthe said alkyl groupcon' tains more than two carbonatoms.

15. A soap stabilized againstthe' development or oolorfand ranciditybyhaving incorporated" therein a small amount oi Nf-phenyl thiourethane.16. A soap stabilized against. the development.

of color andranoldity by having incorporated I therein a small amountofN-phenyl butylthiourethane.

17.;A soap stabilized against the development or color and rancidity byhavlngyincorporated therein a small amount 01' N-cyclohexylthiourethane. r GEORGE D.

